This invention pertains to tractors, especially farm tractors where a relatively short radius turn may be desirable in field use. It also may be used on any other vehicle in which a short turning radius is required.
Farm tractors are almost universally used not only for planting farm fields, but also for cultivating and often for harvesting crops. Particularly in the growing of row crops such as corn, cotton, and soy beans, the tractor, upon reaching the end of a row, is expected to make a relatively short-radius turn so that other parallel rows may then be followed. The parallel row may not necessarily be immediately adjacent the completed row, but is preferably not very remote. Further, the arc at the end of the row should be kept to a reasonably short radius so that the width of the crossing rows at the end of field is kept small thus keeping the wasted space to a minimum.
There are other vehicles, such as fork lift devices, which also require a short turning radius because of narrow aisles in warehouses. The mechanism proposed here may also be useful for such devices.
The turning radius for many present farm tractors, especially the large front wheel drive tractors having large traction wheels, is limited because of the space between the steered wheels and the body of the tractor. As the steered wheel is turned, the tire approaches contact with the body of the tractor. Stops then prevent further turning to avoid interference between the wheel and the tractor body. To avoid this problem, the present invention provides for extension of the axles when the steering gets to the sharpest turn.